Method and apparatus for receiving digital video signals

Abstract

A method and apparatus for storing a compressed video stream or an uncompressed video stream is disclosed. The uncompressed video stream may be ZOOM VIDEO data. The compressed video stream may be a TRANSPORT STREAM data from a High Definition Television (HDTV) broadcast. A video graphics adapter is configured to properly receive one of the two types of video data. The received data and control signals are monitored to provide a second set of control of data signal which are used by a packer and an window control to provide data of a predetermined width and control to an address generator. The data is buffered within a graphics memory such as a frame buffer. The graphics memory can be written to system memory when full, or accessed by the system memory controller during the fill operation if a multi-ported memory is used.

1. A video graphics system comprising:
 a transport stream port to receive a digital video transport stream, the digital video transport stream including a data stream and control signals; 
 a transport stream interface control having an input coupled to the transport stream port, and having a first output port to provide a set of control signals, and a second output port to provide video graphics data; and 
 a data storage controller having a first input port coupled to the first output port of the transport stream interface control to accept the set of control signals of the transport stream interface control, a second input port coupled to a second output port of a transport stream interface control to accept video graphics data, an output address port to provide an address value, an output video data port to provide video data, and at least one pair of a plurality of internal control ports to communicate control signals within the data storage controller. 
 
     
     
       2. The system of  claim 1  further comprising:
 a memory having a first port coupled to the output video data port of the data storage controller and a second port coupled to the address port of the data storage controller. 
 
     
     
       3. The system of  claim 2 , wherein the memory is a frame buffer memory. 
     
     
       4. The system of  claim 2  further comprising:
 a system bus interface having a first port coupled to a third port of the memory, and a second port coupled to a fourth port of the memory. 
 
     
     
       5. The system of  claim 4 , wherein the third port of the memory is substantially the same as the second port of the memory. 
     
     
       6. The system of  claim 1 , wherein the digital video transport stream is a digital video broadcast transport stream. 
     
     
       7. The system of  claim 6 , wherein the control signals of the digital video transport stream include a clock signal, a synchronization signal, and a data valid signal. 
     
     
       8. The system of  claim 7 , wherein the set of control signals of the transport stream interface control includes a start of field signal to indicate the start of a frame of video. 
     
     
       9. The system of  claim 8 , wherein the set of control signals of the transport stream interface control signal includes a valid data output to indicate when data on the second output port of the transport stream interface control is active video data. 
     
     
       10. The system of  claim 9 , wherein the set of control signals of the data storage controller includes a valid vertical blanking interval signal to indicate when data on the output video data port of the data storage controller is present during a vertical blanking interval. 
     
     
       11. The system of  claim 7 , wherein the control signals of the digital video transport stream further include an error signal, indicating there is an error in the transport stream. 
     
     
       12. The system of  claim 6 , further comprising:
 a first video port to receive digital video of a first type, wherein the first type is not digital video broadcast stream video; 
 a first video interface control having an input coupled to the first video port, and having a first output port to provide the set of control signals, and a second output port to provide video graphics data; and 
 a select node coupled to the transport stream interface control and to the first video interface control. 
 
     
     
       13. The system of  claim 12 , wherein the first video port is a zoom video port. 
     
     
       14. The system of  claim 12 , wherein the first video port is a digital video stream port. 
     
     
       15. The video graphics system of  claim 1  comprising:
 a packer; 
 a window control; and 
 an address generator, wherein the packer is operative to pack data into a format that is compatible with a frame buffer memory, the window controller is operative to control the amount of data written into the frame buffer memory, and the address generator is operative to generate proper frame buffer addresses for data from the transport stream, and wherein the frame buffer addresses comprise addresses corresponding to a predefined area of the frame buffer. 
 
     
     
       16. A method of receiving video graphics data, the method comprising:
 receiving a compressed transport stream associated with a digital video broadcast signal, the compressed transport stream having data signals and control signals; 
 generating a secondary set of memory control signals from the compressed transport stream's control signals; 
 storing at least a portion of the compressed transport stream data signals via a first bus in a memory buffer controlled by the secondary set of memory control signals wherein the memory buffer comprises a frame buffer that stores uncompressed data in a different mode of operation; and 
 sending at least the portion of the compressed transport stream data stored in the memory buffer via the first bus to a system bus. 
 
     
     
       17. The method of  claim 16 , further comprising:
 wherein the receiving, generating and storing occur when in a first mode of operation; 
 during a second mode of operation, performing: 
 receiving a digital video signal having data signals and control signals, wherein the digital video signal is of a different type than the compressed transport stream; 
 generating the secondary set of control signals from the digital video signal's control signals; and 
 storing at least a portion of the digital video signal in the memory buffer based on the secondary set of control signals. 
 
     
     
       18. The method of  claim 17 , wherein the video signal is a zoom video signal. 
     
     
       19. The method of  claim 16  wherein the secondary set of control signals from the compressed transport stream indicate at least: that a first byte of a transport stream packet is to be stored in the frame buffer, a first byte of the transport stream packet and a last byte of the transport stream packet. 
     
     
       20. A system for receiving a digital video broadcast signal, the system comprising:
 a tuner to receive a digital video broadcast signal and to provide an analog output signal; 
 a demodulator coupled to receive the analog output signal from the tuner, and to provide a compressed transport stream; 
 a video graphics adapter having a transport stream port to receive the compressed transport stream and another transport stream, the video graphics adapter further includes a bus interface port coupleable to a central processing unit, and further includes a graphics engine and a video output port; 
 wherein the video graphics adapter is operative to store at least a portion of compressed transport stream data signals to be at first in frame buffer memory controlled by a secondary set of memory control signals derived from the compressed transport streams control signals, and storing uncompressed data in the frame buffer memory in a different mode of operation. 
 
     
     
       21. The system of  claim 20 , wherein the video graphics adapter includes:
 memory operably coupled to the graphics engine, the transport stream port and to the bus interface port to store at least a portion of the compressed transport stream and coupled to store data for the graphics engine wherein the memory comprises frame buffer memory. 
 
     
     
       22. The system of  claim 20 , further comprising:
 a central processor unit coupled to the bus interface port of the video graphics adapter; and 
 a transport demultiplexor coupled to a demodulator. 
 
     
     
       23. A method of receiving video graphics data, the method comprising:
 receiving a compressed transport stream associated with a digital video broadcast signal, the compressed transport stream having data signals and control signals; 
 generating a secondary set of control signals from the compressed transport stream's control signals; 
 storing at least a portion of the compressed transport stream data signals via a first bus in a memory buffer controlled by the secondary set of control signals wherein the memory buffer comprises a frame buffer that stores uncompressed data in a different mode of operation; 
 sending the at least portion of the compressed transport stream data stored in the memory buffer via the first bus to a system bus; 
 wherein generating the secondary set of control signals comprises generating frame based control signals to store the compressed transport stream data in the frame buffer wherein transport stream packets containing compressed data are stored in the frame buffer memory based on display frame control signals; and 
 wherein the secondary control signals include a start of frame control signal indicating that a first byte of transport stream packet is to be stored in the frame buffer, a start of active frame control signal indicating the first byte of transport stream packet, and end of active frame control signal indicating the last byte of a transport stream packet and a deactive control signal that is asserted to indicate invalid bytes are present in the compressed transport stream.